LMX1600EVAL National Semiconductor, LMX1600EVAL Datasheet - Page 11

• Manufacturer Part Number: LMX1600EVAL
• Manufacturer: National Semiconductor

Specifications of LMX1600EVAL

• Lead Free Status / Rohs Status: Not Compliant

2.0 Programming Description
2.4 CHARGE PUMP CONTROL WORD (CP_WORD)
AUX_CP_GAIN (MAIN_R[17]) and MAIN_CP_GAIN (MAIN_R[16]) are used to select charge pump current magnitude either low
gain mode (160 µA typ) or high gain mode (1600 µA typ)
AUX_ PD_POL (MAIN_R[15]) and MAIN_ PD_POL (MAIN_R[14]) are respectively set to one when Aux or Main VCO
characteristics are positive as in (1) below. When VCO frequency decreases with increasing control voltage (2) PD_POL should
set to zero.
2.4.1 VCO Characteristics
2.4.2 Phase Comparator and Internal Charge Pump Characteristics
(AUX_PD_POL/MAIN_PD_POL = 1)
Note 15: fr is phase detector input from reference counter. fp is phase detector input from programmable N counter.
2.5 F
MAIN_CP_GAIN
AUX_CP_GAIN
MAIN_PD_POL
AUX_PD_POL
OUT
AUX_R[17]
Phase difference detection range: - 2π to + 2pπ.
The minimum width pump up and pump down current pulses occur at the CPo pin when the loop is locked.
/LOCK DETECT PROGRAMMING TRUTH TABLE (FoLD)
BIT
3
0
0
0
MSB
AUX_CP_GAIN
AUX_R[16]
2
0
0
0
MAIN_R[17]
MAIN_R[16]
MAIN_R[15]
MAIN_R[14]
LOCATION
FoLD
AUX_R[15]
1
0
0
1
MAIN_CP_GAIN
Aux Charge Pump Current Gain
Main Charge Pump Current Gain
Aux Phase Detector Polarity
Main Phase Detector Polarity
(Continued)
AUX_R[14]
X
0
0
1
FUNCTION
11
AUX_PD_POL
Fo/LD OUTPUT STATE
10012914
Main Lock Detect
MAIN_PD_POL
“0”
“1”
Negative
Negative
LOW
LOW
0
LSB
10012915
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Positive
Positive
HIGH
HIGH
1